INTEGRATEDMANAGEMENT OF ONION THRIPS (Thrips tabaci L.) AND ITS EFFECT ON ONION GROWTH AND YIELD (Allium cepa L.) UNDER IRRIGATION CONDITIONS IN GUBALAFTO DISTRICT, NORTH EASTERN ETHIOPIA

Abstract

Onion thrips is an insect pest that limits onion production and results in 26–57% output losses. Hence, a field experiment was carried out in the Gubalafto District of Ethiopia to create environmentally friendly management using intercropping vegetable and onion varieties. Three onion cultivars were used in the main plot treatment: Bombay red, Adama red, and Nafis. In the subplot treatments, tomatoes, carrots, and lettuce were intercropped with onions. Three replications of the study were carried out utilizing a split plot arrangement and a randomized complete block design. Ten randomly selected pre-tagged onion plants were used to gather data on the number of banded onion thrips and processed using SAS. The results demonstrated a reduction in onion thrips per plant when onion types were intercropped with vegetable treatments. The intercropping of Bombay red with tomato and Nafis with carrot decreased the population of onion thrips by 54.61% and 71.14%, respectively. Similarly, there was a significant decrease in the degree of thrips damage by 28.03% when Nafis was intercropped with carrots, with the maximum yield of onions (40.13 t/ha) achieved and the lowest (24.56 t/ha) from Adama red cropping alone. Carrots and Nafis intercropping had the highest gross income. The plot treated with Adama red had the lowest gross income. Intercropping onions with other vegetables, like carrots, was found to be effective in reducing the quantity of onion thrips and their damage to onions. As such, it can be a crucial part of the integrated management of onion thrips.